1. Field of the Invention
The present invention relates to a beverage dispenser for dispensing a beverage into a container such as a cup. More particularly, this invention is related to a beverage dispenser that inhibits dispensing of the beverage when the container into which the beverage is dispensed is full.
2. Description of the Related Art
Beverage dispensers are used in many locations to deliver individual portions of beverages into drinking containers such as glasses or cups. Some, but not all, beverage dispensers mix a concentrate of the beverage with water, which may be carbonated, immediately prior to the actual discharge of the beverage into the container. Beverage dispensers of this type are used in restaurants and entertainment venues such as movie theaters and sports arenas. Some restaurants locate these dispensers in a public space so that patrons can obtain their own drinks. An advantage of so locating a beverage dispenser is that it frees the restaurant staff for other duties.
Many beverage dispensers, especially those designed to deliver cold beverages such as soft drinks and fruit drinks, include a dispensing head from which a nozzle extends. A lever is pivotally mounted to the dispensing head behind the nozzle. Located behind the nozzle are the concentrate containers, a water source and the fluid pumps and valves that control dispensing. The lever is shaped so that, for a person to obtain a beverage, the individual pivots the lever with the container as a consequence of positioning the container under the nozzle. A sensor integral with the dispensing system monitors the displacement of the lever. Based on this sensor generating a signal indicating that the lever has been displaced, a control circuit, also part of the dispensing system, opens the appropriate valve(s) and/or actuates the pump so as to force the discharge of the beverage.
Inevitably, when such a dispensing system is employed, persons using it will place containers underneath the nozzle for such a period of time that the amount of beverage discharged will first fill and then overflow the container. This overflowing occurs for a number of reasons: inattention to the dispensing process; an individual's desire to fill the container to the top; or simple mischievousness. These latter causes of container overfill are especially prone to occur when the dispensing system is placed in a location where patrons, not employees, use the system.
One disadvantage of this overflow problem is that it wastes beverage. A second disadvantage is that it creates needless liquid waste that must be contained and disposed.
A number of methods have been proposed to reduce, if not eliminate, the incidence of container overfill. One method that has been proposed is monitoring the volume of beverage discharged. Once the monitoring assembly determines that a volume of beverage sufficient to fill the container has been delivered, the dispensing system cuts off delivery of additional beverage. One disadvantage of this type of system is that at many locations where these dispensing systems are used, different sized containers are typically available. This means an individual must take the time to push the start button associated with the container to be filled in order to ensure that the container is properly filled. At a self-serve location, many patrons do not want to take the time in order to make sure they have properly actuated the dispensing system.
Another method that has been employed to minimize overfill involves real time monitoring of whether or not, beverage, upon being dispensed, is overflowing out of the container. This monitoring is accomplished by applying a current to the beverage. Typically, this current is applied by a probe integral with the nozzle from which the beverage is dispensed. The lever the individual pushes to actuate the dispenser functions as a second probe. As long as the dispensed beverage flows into the container, there is no conductive path between the two probes. Once beverage overflows the container, a fraction of the beverage stream flows over the lever. Since beverages are electrically conductive, the beverage forms a conductive current path between the nozzle probe and the lever. A sensing circuit monitors whether or not there is current flow through this circuit. When current flow is detected, the sensing circuit sends a signal to the dispenser controller so as to cause the system to stop dispensing.
The above-described system has some utility for detecting whether or not beverage is overflowing from a container. However, the signal path of this two probe circuit tends to be noisy. One solution to this problem, applying a high current to the one probe and monitoring the second probe is clearly unacceptable for safety reasons. Therefore, presently, in a dispensing system wherein this type of overflow monitoring/actuation control subs-system is employed, the sub-system is configured so that the detection of any low level current flow between the probes deactivates the system. A disadvantage of this arrangement is that, due to the presence of stray liquids around the dispensing system, the monitoring-actuation control system will sometimes generate a false positive signal that the beverage is overflowing the container when this event is not occurring. The resultant deactivation of the dispensing system even though a container is not completely full then becomes an irritant to the person trying to obtain a full cup of beverage.